The colonoscopy is the reference examination for the diagnosis of neoplastic lesions in the colon and rectum. Mass screening assessment studies have shown that colonoscopic detection and removal of adenomas in patients selected through fecal occult blood test reduces colorectal cancer incidence and mortality. However, the literature has reported interval cancer cases or adenomas, probably "missed" by the colonoscopy. In theory, using coloured warm water could improve colon preparation by mobilizing the residual faeces, decreasing the colic spasm and increasing the visualization of the pit pattern. Preliminary American studies, led by Leung et al, have shown a very clear increase in the adenoma detection rate.